Sir Alex Ferguson has admitted Phil Jones will probably miss Manchester United's Champions League clash with Real Madrid, while there are still doubts over the fitness of striker Wayne Rooney for this weekend's trip to Queens Park Rangers.

Jones left Old Trafford on crutches after injuring his right ankle in a challenge with Reading's Jobi McAnuff during United's 2-1 win in the FA Cup, and Ferguson believes he is likely to be without the 21-year-old for the game against the Spanish champions on March 5.

He said: "Phil Jones is the one we're concerned about for the Real Madrid game. We're working hard on it and I'd say he has an outside chance - no more than that. We'll have to wait and see if he's fit for the second leg. It's two weeks away. A lot can happen. He's an outside chance, that's all."

Jones could be a significant loss for United given his inspired performance in the 1-1 draw in the first leg at the Bernabeu, and Ferguson said that it was precisely because of his bravery that he had suffered the injury.

"Phil tackled awkwardly the other night and tangled his foot there," he said. "That's why he has the injury he has. He has the courage and willingness to tackle. Bryan Robson was the same. Bryan couldn't see danger and neither can Phil. It's a measure of his courage and I don't want to take that away from him.

"Phil did an incredible job in Madrid. He doesn't care who he's playing against, he has no fear of playing against anyone. When you look at his tackles, he tackles like a young man. Maybe he's too brave. He was unbalanced in the tackle and ended up injured."

Ferguson did not give any update on the condition of Rooney, who missed Monday's FA Cup win over Reading and much of this week's training with a sinus infection. However, one report suggests that the England forward is likely to miss Saturday's trip to Queens Park Rangers as well, though this is yet to be confirmed by United.

Should Rooney miss the fixture in west London he will have at most just one more game - the home clash against Norwich city on March 3 - to regain match fitness before Real come to Old trafford three days later.

United go to Loftus Road on Saturday in a match of the Premier League's top and bottom teams with Ferguson saying it is difficult to select his side.

The Scot made eight changes for the win at Reading and - apart from Jones, Paul Scholes and Darren Fletcher, who is out for the season - reported a clean bill of health, meaning he has plenty of players pressing for a starting place.

He added: "We have a problem picking teams at the moment but that's where we want to be."

While QPR have only won two league games all season and United could go 15 points clear of Manchester City, who face Chelsea on Sunday, Ferguson is anticipating a tough game.

The United manager also said it is inevitable his side will drop points over the next three months.

He said: "QPR are fighting for survival and we know it's going to be a hard game. That's what we need - we need to make sure we do our job right. The fact is, City will drop points too. That's where we are, coming into the run-in. We expect to drop a few points but so will they. It's always a hard run-in in the Premier League. With the right attitude and the right players we have a chance."